Wood stove radon reduction system

ABSTRACT

A combination of a wood stove and radon collecting system. A radon collection tube located in the basement of a building is connected via conduit leading into the combustion chamber of the stove. Burning wood within the combustion chamber is operable to normally cause radon within the building to flow into the radon collection tube, through the combustion chamber and then out through an exhaust tube. In the absence of burning wood, a lighted candle is placed in the combustion chamber tube to cause the radon within the radon collection tube to flow into the combustion chamber and then out through the exhaust tube.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of application Ser. No. 11/423,180, filed Jun. 9, 2006 which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to the field of wood stoves.

2. Description of the Prior Art

In certain areas of the country, radon collects in the basements of buildings. Typically, a blower connected to a collection tube extending outwardly from the building is operable to force the radon gas from the building. The collection tube may extend into the basement or beneath the basement or building slab. A blower is required adding not only to the initial cost of the system but also requiring maintenance and electricity. What is needed is a radon collection system that will use the heat within the heating system to force the radon from the building. Further, there is a need to combine such as system with a wood burning stove or candle burning due to likelihood of power failure in warm weather. Disclosed herein is such a combination and system.

U.S. Pat. No. 4,877,182 issued to Pugh et al. discloses a typical crawl space ventilation system to eliminate radon gas from the building. U.S. Pat. No. 4,905,579 issued to Dame discloses a plurality of blowers with control valves to control the pressure within the building thereby controlling the flow of radon into the building. U.S. Pat. No. 3,175,552 issued to Sutton discloses a wood burning fireplace having a blower motor for forcing air via the burning logs through the heating outlets extending throughout the room. In order to accelerate the draft out of the chimney of an incinerator, U.S. Pat. No. 3,134,345 issued to King discloses a blower for accelerating the draft through the chimney of the incinerator. Preheated air is ejected into the furnace combustion chamber in U.S. Pat. No. 4,262,608 issued to Jackson.

A number of combinations of heating systems and radon collection systems have been combined in an attempt to minimize radon gas within a building. For example, U.S. Pat. No. 5,191,874 issued to McWilliams discloses a blower for collecting radon gas from inside the building and then directing the gas to the gas outlet of a furnace. U.S. Pat. No. 4,244,686 issued to Scott discloses a method of improving the operating economy of a furnace by supplying to the heating chamber various gases including radon gas. Further, U.S. Pat. No. 4,920,866 issued to Hoban discloses the combination of a wood stove with a tube for collecting radon gas within a building which is injected into the outlet of the stove.

Wood stoves include a door which may be pivoted open for insertion of wood into the combustion chamber. By using such a stove, I have combined a radon collection tube which may be conveniently inserted via the door to direct the radon gas directly into the combustion chamber. Thus, the radon collection system may be conveniently connected or disconnected from the stove by positioning the radon collection tube through the door opening while at the same time inserting additional wood into the combustion chamber.

In moderate climates, the wood burning stove is not utilized to heat the building at all times since the outside ambient air is sufficiently warm not to require the heating of the interior air of the building. In these cases, wood burning stoves do not have wood burning within the combustion chamber at all times and instead the air within the combustion chamber is relatively cool. In such a condition, the stove does not expel radon from the building. I have therefore devised a method and heating system which utilizes a lighted candle within the combustion chamber when the chamber is void of burning wood and similar materials. A candle has sufficient heat to warm the gas within the combustion chamber thereby drawing the cooler radon gas within the radon collecting tube leading into the chamber; however, the candle does not generate enough heat to heat the building. Thus, the system is operable to remove radon from the building both when burning wood and heating the building and in a non-heating condition by placing a lighted candle within the stove.

SUMMARY OF THE INVENTION

One embodiment of the present invention is a stove for reducing radon gas in a building both when the stove is in a first condition heating the building and in a second condition not heating the building. The stove's main body has a combustion chamber and an opening leading into the chamber. A door is mounted to the stove's main body and is movable from a first position uncovering the opening to a second position extending across the opening. A radon collecting tube is mounted to the stove's main body and has a proximal end opening into the chamber and a distal end opening into the building. Burning wood is located in the chamber when the stove is in a first condition heating the building and gas within the chamber to draw radon gas from the tube into the chamber. A burning candle is located in the chamber when the stove is in a second condition not heating the building to heat gas within the chamber to draw radon gas from the tube into the chamber.

It is an object of the present invention to combine a wood stove with a radon collection system.

A further object of the present invention is to provide a new and improved wood stove.

Yet an additional object of the present invention is to provide a radon collection system that may easily be adapted to a conventional wood stove.

A further object of the present invention is to provide a heating system which is operable to withdraw radon from the building when the system is both in a heating mode and a non-heating mode.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary schematic representation of the stove and radon collection system incorporating the present invention installed within a building.

FIG. 2 is an enlarged front view of the stove of FIG. 1 with the stove door shown in the open position.

FIG. 3 is a side view looking in the direction of arrows 3-3 of FIG. 2 with the radon collection tube removed from the stove.

FIG. 4 is the same view as FIG. 3 only showing the stove door partially closed with the radon collection tube installed between the door and stove.

FIG. 5 is an enlarged fragmentary top view looking in the direction of arrows 5-5 of FIG. 4 and viewed in the direction of the arrows.

FIG. 6 is a fragmentary and enlarged view of the radon collection tube 21 mounted in the stored position on the stove.

FIG. 7 is the same view as FIG. 2 only showing a pile of wood on fire within the combustion chamber.

FIG. 8 is the same view as FIG. 2 only showing a lit candle within the combustion chamber.

FIG. 9 is a top view of the stove of FIG. 2 showing the cook top.

DESCRIPTION OF THE PREFERRED EMBODIMENT

For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

Referring now more particularly to the FIG. 1, there is shown in fragment a building 10 having a roof 11, an interior room 12, and basement 13. A wood stove 16 is positioned within room 12 and has a conventional outlet flue 17 extending through the roof 11 to allow the exhaust gases from the stove to escape the building. A radon collection system 18 is provided to collect radon gas from the basement by a perforated tube 19, in turn, connected by conduit 20 and tube 21 that extends between the stove door 30 and the main body 23 of stove 16 allowing the radon gas to enter the combustion chamber of the stove. A second conduit 24 extends through the roof 11 allowing gas collected by tube 19 to exit the building when valve 25 is positioned to allow the gas to flow from tube 19 through conduit 24 while blocking flow of gas into tube 20. Likewise, valve 25 has a second position blocking flow of gas from tube 19 through conduit 24 but allowing the gas to flow from tube 19 through conduit 20 to tube 21. An optional inlet tube 26 extends through the wall of the house to the external environment with a fan 27 provided to blow external air into the basement 13 thereby pressurizing the basement and forcing the radon from the building.

Wood stove 16 has a main body 23 positioned atop a base 28 (FIG. 2) spacing the main body of the stove above the floor. A combustion chamber 29 is formed within main body 23 with exhaust outlet 17 leading therefrom. Door 30 is pivotally mounted by conventional hinges 31 and 32 to the front 33 of the stove. The door may be pivoted from an open position (FIG. 2) through an intermediate position (FIG. 4) to a completely closed position overlapping opening 34 leading into combustion chamber 29. A handle 35 (FIG. 1) is provided on the exterior surface of door 30 to facilitate the opening and closing of the door.

Wall 36 (FIGS. 2 and 3) extends around opening 34 and projects outwardly from the forward facing surface 37 of the stove main body 23. Wall 36 has a lower portion 38 and an upper portion 39 extending across respectively the bottom and top of opening 34. Further, a pair of side portions 40 and 41 (FIG. 2) extend vertically along the opposite sides of opening 34. Portions 38 through 41 form a ledge 42 (FIG. 3) that extends around the opening. Side portion 40 includes a recess 43 formed therein to receive tube 21 connected to the radon collection system.

Tube 21 may be removed from recess 43 to allow door 30 to extend sealingly across opening 34 with the exception that air is allowed to flow through recess 43 into the combustion chamber. When tube 21 is not mounted within recess 43, it is stored in a vertical position in holder 45 mounted to the front surface 37 of the furnace main body. Holder 45 consists of a semi-circular recess 46 (FIG. 6) forming a pair of outwardly extending arms 47 and 48 between which tube 21 may be positioned. A magnet 49 is mounted on the front surface 37 of the stove and is positioned to magnetically hold the metallic tube 21 in place. Alternatively, a magnet may be mounted to tube 21 to secure the tube to holder 45. In such a case, magnet 49 is not necessary.

In order to position tube 21 to extend into the combustion chamber opening, tube 21 is grasped and pulled apart from holder 45. The end of tube 21 is then inserted through recess 43 and into the opening 34 allowing gases within the tube to enter the combustion chamber. Suitable magnets 50 are provided on the front surface 37 of the stove main body immediately adjacent recess 43 to magnetically and removably hold tube 21 in recess 43.

The external size of tube 21 is such that when installed within recess 43 it projects outwardly of the end or edge of wall 36. For example, the radius of recess 43 may be approximately one-half the diameter of tube 21 if a cylindrical tube is utilized thereby providing for the remaining half of the tube to project outwardly from wall 36. In such a case, stove door 30 will be prevented from closing in a completely sealed position relative to combustion chamber opening 34 creating a gap 51 that extends between the edge 52 (FIG. 5) of wall 36 and the inwardly facing surface of door 30. In order to limit air flow through gap 51, a plurality of aluminum sheets are removably mounted to extend from wall 36 across gap 51 and the sides of door 30. For example, a plurality of aluminum sheets 53 (FIG. 5) are fashioned to fit externally around wall 36 being secured in place by magnets 54 attaching the sheets to the stove. The sheets then extend across gap 51 limiting the flow of air through the gap when the door has been moved to an intermediate position located between an open position depicted in FIG. 3 and the completely closed position when the tube 21 is removed from recess 43. Additional magnets may be used to secure aluminum strips 53 to sides 61 of the door. That is, magnets 54 may be used to secure strips 53 directly to the stove or directly to the door. Likewise, magnets 54 may be used to secure the metal strips 53 to both the stove and door with the object being to position and hold the metal strips across gap 51 when the door extends over opening 34 but spaced partially away from the stove main body forming gap 51 due to the presence of tube 21 in recess 43. Strips 53 may be extended on the outwardly facing surface of portions 38-40 to thereby reduce the flow of air via gap 51.

With valve 25 positioned to allow gas flow from tube 18 into conduit 20 and not conduit 24, any radon within basement 13 is allowed to flow into perforated tube 19 and then into the combustion chamber of the stove when tube 21 is mounted to recess 43. By turning on fan 27 forcing external air to flow into the basement via conduit 26, the basement may be purged of radon gas. Tube 21 forms an air spout for collection of air including radon gas within the basement and directing same via opening 34 into the combustion chamber.

Combustion within the stove causes the gas within the combustion chamber to be hotter than gas within tubes 21, 20 and 19 thereby drawing up air and radon from the basement through tube 19 and eventually out of flue 17. After valve 25 is closed to tube 20 and opened to tube 24, spout 21 is removed from recess 43, the draft is broken and radon will not flow up to stove 16. No cap is needed to extend across recess 43. Valve 25 is in a position blocking flow into conduit 20 while allowing gas flow from tube 18 to conduit 24.

Many variations are contemplated and included in the present invention. For example, the drawing depicts a building have a basement; however, the radon collection system may also be used where the building does not have a basement. In such a case, the radon collection tube may be positioned beneath the slab supporting the building.

In order to continue to reduce radon within the building both when the stove is in a first condition heating the building and in a second condition not heating the building, there is disclosed herein a system that utilizes burning wood in the combustion chamber for heating the building and the gas within the chamber whereas only a lighted candle is placed in a combustion chamber so as to heat the gas within the chamber but not the building. FIGS. 6, 7 and 8 disclose the same stove shown in FIG. 2 with the burning wood 70 depicted in the combustion chamber in FIG. 7 and the lighted candle 71 positioned within the combustion chamber in FIG. 8. Thus, the wood stove 16 has a main body 23 positioned atop a base spacing the main body of the stove above the floor. A combustion chamber 29 is formed within main body 23 with exhaust tube 17 leading therefrom. Door 30 is pivotally mounted by conventional hinges 31 and 32 to the front 33 of the stove. The door may be pivoted from an open position (FIG. 2) to an intermediate position (FIG. 4) to a completely closed position overlapping opening 34 leading into combustion chamber 29. A radon collecting tube 21 is mounted to the stove as previously detailed herein and has a proximal end opening into chamber 29 and a distal end opening into the building such as depicted in FIG. 1. The radon collecting tube 21 is connected to a perforated tube 19 located in the basement of the building with a valve 25 operable to control the flow of gas within tube 19 to either the radon collecting tube 21 or an exhaust tube 24, in turn, venting to the atmosphere.

A stack of burning wood 70 (FIG. 7) is located within chamber 29 when the stove is in the first condition for heating the building and the gas located within the chamber thereby elevating the temperature of the gas within chamber 29 as compared to the lower temperature gas within radon collecting tube 21. The resulting differential in temperature causes the radon gas within tube 21 to flow into chamber 29 and eventually exhausted via exhaust tube 17 leading from the combustion chamber to external of the building.

In FIG. 8, the burning wood has been replaced with a lighted candle 71 which barely generates enough heat to elevate the gas within chamber 29 when door 30 is closed resting against radon collecting tube 21 with the candle not being of sufficient size to generate heat to heat the building. For example, a typical candle of four to five inches in height and three inches in diameter will heat the gas within chamber 29 when the radon collecting tube 21 extends into opening 34 with door 30 resting against the radon collecting tube as illustrated in FIG. 4. On the other hand, a typical house, for example, of 1000 square feet or more, will not have the temperature of the air within the building raised by a single candle burning in the combustion chamber as compared to burning wood positioned within the chamber. On the other hand, the burning candle is adequate to elevate the temperature of the gas within the combustion chamber thereby drawing the relatively cooler radon gas in tube 21 into the chamber and then out exhaust vent 17.

The radon collecting tube 21 extends from the basement as a single tube or a plurality of tubes such as shown in FIG. 1. Further, a fresh air conduit 26 leading from external of the building into the basement has a fan 27 (FIG. 1) forcing outside fresh air through the conduit into the basement. As a result, as the air with radon is expelled from the building through exhaust tube 17, external air flows into the building via conduit 26 eventually replacing all of the radon gas within the building with fresh air.

Radon collecting tube 21 is removably held by magnet 50 in recess 43 so as to open into opening 34 leading to the combustion chamber. In this position, door 30 may extend across opening 34. The radon collecting tube when installed within recess 43 extends outwardly of wall 36. As a result, door 30 contacts radon collecting tube 21 when the door extends across the opening creating gaps 51 between the door and edge 52 (FIG. 5) of wall 36. Aluminum sheets 53 (FIG. 5) mounted to wall 36 and door 30 surround the combustion chamber opening limiting flow of air through the gaps between the door and wall 36.

A series of measurements reflect the advantage of placing a lighted candle into the stove combustion chamber. For example, with wood burning in the stove and fan 27 on as shown in the drawings, the radon on the higher first floor of the building measured 5.0 picocuries per liter (pCi/L) while at the same time the radon in the lower basement was 5.4 pCi/L. When the stove is not burning wood, a lighted candle may be placed in the combustion chamber. Measurements were taken in such a case, i.e. the stove was not burning wood and having a lighted candle therein. In such a case, power to the building was turned off due to a storm thereby turning off fan 27 with the lighted candle within the chamber with the radon detected within the combustion chamber rising from 4.9 pCi/L to 9.0 pCi/L to 16.7 pCi/L to 18.4 pCi/L. At the moment the power was turned back on thereby operating fan 27, the radon initially measured in the combustion chamber was 20.6 pCi/L while the radon in the basement measured 16.2 pCi/L. Over a period of time, with the candle in a lit condition in the combustion chamber and with fan 27 in operation, the radon in the combustion chamber rose from 20.6 pCi/L to 21.7 pCi/L to 21.8 pCi/L while at the same time the radon measured in the basement deceased from 16.2 pCi/L to 14.2 pCi/L to 12.6 pCi/L. With fan 27 in operation to bring fresh air into the basement, the radon in the basement decreased as the heat provided in the combustion chamber by the candle was operable to draw the radon up from the basement and into the combustion chamber. Thus, the radon in the combustion chamber decreased from 21.8 pCi/L to 21.3 pCi/L to 14.7 pCi/L to 6.8pCi/L as it rose up through the stove pipe and eventually stabilizing at 3.7 pCi/L. During the same period of time, the radon in the basement decreased from 12.6 pCi/L to 11.2 pCi/L to 8.1 pCi/L to 4.5 pCi/L and eventually stabilizing at 4.6 pCi/L. In other words, the radon levels in the combustion chamber having the lighted candle therein increased while the radon in the basement decreased until eventually the radon in the combustion chamber began to decrease over a period of time as less radon was available in the basement to withdraw into the combustion chamber.

The method of reducing radon in a building includes the step of first providing a stove having a combustion chamber for burning wood with a door movable over the opening of the chamber from a first position whereat the door uncovers the opening to a second positioning extending across the opening. A radon collecting tube opens into the chamber with the opposite end opening into the building. An exhaust tube leads from the chamber to external of the building to exhaust gas within the chamber. The door is moved to the open position with wood located within the chamber being lighted to heat the building and the gas within the chamber thereby drawing radon gas from the radon collecting tube into the chamber and eventually out through the exhaust tube. Immediately after the wood is lit, the door is moved to the position wherein the door extends across the chamber opening. Eventually, the wood is allowed to cool with the stove then being in a non-heating condition. The door may then be opened and a candle is placed into the combustion chamber assuming the chamber is cool and void of the burnable wood. The candle is then lit to heat the gas within the chamber causing sufficient heat in the chamber to draw radon gas from the tube into the chamber. The door is then moved to the position extending across the opening.

In one experiment, the candle having a diameter of three inches and being approximately four to five inches in height generated sufficient heat within the combustion chamber to cause the relatively cool radon gas within the radon collecting tube to flow into the combustion chamber while at the same time, the heat generated by the candle was sufficiently small so as to not heat the building and raise the building temperature. Fresh air is forced into the building to replace the gas flowing from the radon collecting tube into the combustion chamber and then out through the exhaust tube. The air may be forced into the building by use of fan 27.

Stove 16 (FIG. 2) includes a top 80 (FIG. 9) with a cook top 81 covering a large opening in stove top 80 leading to the combustion chamber. The cook top 81 is pivotally mounted by a conventional fastener 85 in turn mounted to the top 80 of the stove. Cook top 81 can be lifted up and pivoted atop stove top 80 to the dashed line position 84. The cook top may be made from cast iron. Removable plates 82 and 83 are mounted to cook top 81 and cover openings extending through cook top 81. Plates 82 and 83 may be lifted in an upward direction separating from cook top 81 to determine if the candle 71 is lit and also allowing viewing of the condition of the candle as the candle burns. Normally, the candle is inserted into the stove in a lit condition through the front door of the stove although it is possible to insert the candle through an opening normally covered by one of the plates. Plates 82 and 83 may be mounted to cook top 81 in a variety of conventional ways, such as, providing a ledge within each opening upon which plates 82 and 83 may rest when inserted into the openings.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. 

1. A stove for reducing radon gas in a building both when the stove is in a first condition heating the building and in a second condition not heating the building comprising: a stove main body located in a building and having a combustion chamber and an opening leading into said chamber; a door mounted to said stove main body and movable from a first position uncovering said opening to a second position extending across said opening; a radon collecting tube mounted to said stove main body and having a proximal end opening into said chamber and a distal end opening into the building; a burning wood located in said chamber when the stove is in a first condition heating the building and gas within said chamber to draw radon gas from said tube into said chamber; and, a burning candle located in said chamber when the stove is in a second condition not heating the building to heat gas within said chamber to draw radon gas from said tube into said chamber.
 2. The stove of claim 1 wherein the building has a basement and wherein: said radon collecting tube extends from the basement; and further comprising: a fan; a radon expelling tube extending from the stove main body to external of the building; and, a fresh air conduit leading from external of the building into said basement with said fan forcing outside fresh air through said fresh air conduit into the basement providing external air into the building and replenishment of air with radon expelled from the building through said radon expelling tube.
 3. The stove of claim 2 wherein: said radon collecting tube extends between said door and said stove main body into said opening when said door is in said second position extending across said opening.
 4. The stove of claim 3 wherein: said door is spaced apart from said stove main body when in said second position forming gaps leading to said opening; and further comprising: metal strips mounted to said stove main body at said opening and extending over said gaps when said door is in said second position to limit flow of air through said gaps.
 5. A stove for reducing radon gas both when in a heating condition with burning wood therein and in a non-heating condition with a burning candle therein comprising: a stove main body forming a combustion chamber with an opening; a stove door mounted to said stove main body adjacent said opening and movable from a first position whereat said door is away from said opening so wood or a candle may be inserted through said opening into said combustion chamber to a second position extending across said opening; an air spout mounted to said stove main body at said opening, said air spout having an open proximal end extending into said chamber and a distal end; a first conduit connected to said distal end of said air spout and extending away therefrom to collect radon gas, said first conduit having a proximal end opening via said air spout into said chamber and a distal end opening into said building wherein gas within said chamber is hotter than gas within said first conduit to draw radon gas from said first conduit into said chamber both when the chamber has burning wood therein to heat the building and gas within said chamber and when only a burning candle is located therein to only heat the gas within said chamber while not heating the building.
 6. The stove of claim 5 and further comprising: a second conduit extending from said first conduit; and, a controllable valve associated with said first conduit and said second conduit to direct gas flow through said first conduit and said second conduit.
 7. A stove for reducing radon gas in a building both when the stove is in a heating condition with wood burning therein and a non-heating condition with a lit candle therein comprising: a stove main body for heating a building and having a combustion chamber and an opening leading into said chamber; a door mounted to said main body and movable from a first position uncovering said opening to a second position extending across said opening; a radon collecting tube removably mounted to said stove at said opening and having a proximal end opening into said chamber at said opening and a distal end opening into said building, said tube being sized to position said door at said second position whereat said door extends over said opening but is spaced partially away from said stove main body forming gaps therebetween and wherein said door and said stove form a recess into which said tube extends; a burning wood located in said chamber when the stove is in a heating condition heating the building and gas within said chamber to draw radon gas from said tube into said chamber; a burning candle located in said chamber when the stove is in a non-heating condition not heating the building but heating gas within said chamber to draw radon gas from said tube into said chamber, and, magnets for removably holding said tube at said opening.
 8. A method of reducing radon in a building comprising the steps of: providing a stove having a combustion chamber for burning wood with an opening leading into said chamber, a door movable from a first position whereat said door uncovers said opening to a second position extending across said opening, a radon collecting tube having a proximal end opening into said chamber and a distal end opening into said building, and an exhaust tube leading from said chamber to external of said building to exhaust gas within said chamber to external of said building; moving said door to said first position; placing wood through said opening into said chamber; lighting said wood located in said chamber heating the building and gas within said chamber to draw radon gas from said radon collecting tube into said chamber; moving said door to said second position; allowing any wood within said chamber to cool to a non-heating condition; moving said door to said first position; placing a candle through said opening into said chamber when said chamber is cool and void of wood; lighting said candle within said chamber to heat gas within said chamber to draw radon gas from said tube into said chamber; and, moving said door to said second position.
 9. The method of claim 8 and comprising the additional step of: exhausting gas including radon from within said combustion chamber via an exhaust tube to external of said building both when said wood is burning therein and when said candle is lit.
 10. The method of claim 9 and comprising the additional step of: forcing air from external of said building into said building to replace gas exhausted from said building via said exhaust tube.
 11. The method of claim 10 wherein: said forcing step includes the sub-step of activating a fan to force air external of said building into said building. 